How to set the LDFLAGS in CMakeLists.txt?

Question

I set the CFLAGS in CMake by CMAKE_C_FLAGS. Is something like this to set LDFLAGS?

score 61 · Accepted Answer · edited Sep 17 '22 at 06:03

61

It depends a bit on what you want:

A) If you want to specify which libraries to link to, you can use find_library to find libs and then use link_directories and target_link_libraries to.

Of course, it is often worth the effort to write a good find_package script, which nicely adds "imported" libraries with add_library( YourLib IMPORTED ) with correct locations, and platform/build specific pre- and suffixes. You can then simply refer to 'YourLib' and use target_link_libraries.

B) If you wish to specify particular linker-flags, e.g. '-mthreads' or '-Wl,--export-all-symbols' with MinGW-GCC, you can use CMAKE_EXE_LINKER_FLAGS. There are also two similar but undocumented flags for modules, shared or static libraries:

CMAKE_MODULE_LINKER_FLAGS
CMAKE_SHARED_LINKER_FLAGS
CMAKE_STATIC_LINKER_FLAGS

edited Sep 17 '22 at 06:03

starball

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answered May 22 '11 at 14:44

André

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And CMAKE_STATIC_LINKER_FLAGS for static library: http://www.cmake.org/cmake/help/v3.0/variable/CMAKE_STATIC_LINKER_FLAGS.html – Cofyc Jun 18 '15 at 09:43
Just a link to the recent CMake3.0 description: [CMAKE_EXE_LINKER_FLAGS](https://cmake.org/cmake/help/v3.0/variable/CMAKE_EXE_LINKER_FLAGS.html). Note that the MODULE/SHARED/STATIC flags are already documented (though pretty vaguely). – yman Nov 04 '16 at 14:56
What is the Module flag for? – CMCDragonkai Sep 04 '17 at 06:40
@CMCDragonkai I think it is used for clang module library in macOS. – merito Dec 14 '17 at 07:04
How do you use the defines? `CMAKE_MODULE_LINKER_FLAGS += "-Mprogram.mapfile"` fails. – jww Nov 09 '18 at 21:11
cmake has recently added add_link_options(), similar to add_compile_options() - see https://cmake.org/cmake/help/v3.13/command/add_link_options.html – Bruce Adams Dec 07 '18 at 14:46

score 26 · Answer 2 · edited Feb 10 '17 at 18:37

26

Look at:

CMAKE_EXE_LINKER_FLAGS
CMAKE_MODULE_LINKER_FLAGS
CMAKE_SHARED_LINKER_FLAGS
CMAKE_STATIC_LINKER_FLAGS

edited Feb 10 '17 at 18:37

thiagowfx

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answered May 20 '11 at 20:53

tibur

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score 13 · Answer 3 · answered Aug 04 '17 at 09:48

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If you want to add a flag to every link, e.g. -fsanitize=address then I would not recommend using CMAKE_*_LINKER_FLAGS. Even with them all set it still doesn't use the flag when linking a framework on OSX, and maybe in other situations. Instead use link_libraries():

add_compile_options("-fsanitize=address")
link_libraries("-fsanitize=address")

This works for everything.

answered Aug 04 '17 at 09:48

Timmmm

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Is add_compile_options necessary if I just want to set linker flags? – thomastiger Aug 18 '17 at 09:25
That's for now the best and cleanest way to do it. – Salamandar Dec 05 '17 at 10:19

Simon · Answer 4 · 2013-03-22T05:48:19.543

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You can specify linker flags in target_link_libraries.

edited Mar 22 '13 at 05:48

answered May 20 '11 at 23:13

Simon

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score 4 · Answer 5 · edited May 23 '17 at 12:34

4

For linking against libraries see Andre's answer.

For linker flags - the following 4 CMake variables:

CMAKE_EXE_LINKER_FLAGS
CMAKE_MODULE_LINKER_FLAGS
CMAKE_SHARED_LINKER_FLAGS
CMAKE_STATIC_LINKER_FLAGS

can be easily manipulated for different configs (debug, release...) with the ucm_add_linker_flags macro of ucm

edited May 23 '17 at 12:34

Community

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answered Oct 07 '16 at 09:25

onqtam

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How to set the LDFLAGS in CMakeLists.txt?

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